Aromatic polyamide compositions containing aromatic sulfonimide having an affinity for basic dyes

ABSTRACT

POLYAMIDE COMPOSITIONS COMPRISING AN AROMATIC POLYAMIDE AND AN AROMATIC DISULPHONIMIDE COMPOUND. THE POLYAMIDE COMPOSITIONS ARE USEFUL FOR THE PRODUCTION OF READILY BASIC DYEABLE FIBRES.

"United States Patent Office 3,812,085 Patented May 21, 1974 many No Drawing. Filed July 9, 1971, Ser. No. 161,285

Claims priority, application Germany, July 11, 1970, P 20 34 477.8 Int. Cl. C08g 20/38 U.S. Cl. 260-78 R 7 Claims ABSTRACT OF THE DISCLOSURE Polyamide compositions comprising an aromatic polyamide and an aromatic disulphonimide compound. The polyamide compositions are useful for the production of readily basic dyeable fibres.

This invention relates to fully aromatic or aromatic heterocycle-containing polyamide compositions which show a high affinity for basic dyes, and to a process for their production.

The polyamides which can be obtained by interfacial polycondensation, or by polycondensation in solution, from fully aromatic or aromatic heterocycle-containing diamines and aromatic dicarboxylic acid dihalides usually show no afiinity for basic dyes. In order to enable basic dyes to be used for dyeing aromatic polyamides of this kind, processes have been developed for providing the polyamides with the requisite affinity for these dyes by incorporating acid groups. Thus, it is known that the dye absorption of aromatic polyamides can be improved by the addition of co-condensible carboxylic acid derivatives (US. patent specification No. 3,380,969) or by the addition of co-condensible sulphonic acid derivatives (Dutch patent specification No. 6717240). The addition of cocondensible compounds containing disulphimide structures to aromatic polyamides has also been proposed with the same objective in view.

In the context of the present invention, aromatic polyamides include both fully aromatic and also heterocyclecontaining aromatic polyamides.

As high-temperature-resistant polymers, these aromatic polyamides must satisfy stringent requirements in regard both to tensile strength and to thermal stability. If, however, diamines containing acid groups, for example, are co-condensed in a concentration of from to 10 mol percent (based on the total quantity of diamine), every tenth to twentieth diamine chain member of the original aromatic polyamide chain is replaced in random distribution by a diamine containing an acid group. The result of this is that, although the aflinity for dyes of copolyamides of this kind is greatly increased compared with that of unmodified homopolyamides, the strength and thermal stability properties of these copolyamides are considerably reduced.

It has also been proposed to add to the polyamides, in order to improve their aflinity for dyes, from 3 to 30% by weight of a copolyamide highly enriched with disulphimide groups or of a polyamide containing disulphimide groups. In this way, both the mechanical properties and the thermal properties are more effectively preserved because the fundamental structure of the aromatic homopolyamides is not changed.

It is an object of this invention to provide aromatic polyamide compositions having a high aflinity for basic dyes coupled with considerably improved mechanical and thermal properties can be obtained by adding aromatic mono-, dior poly-disulphimides which do not contain any reactive groups (optionally their alkali metal or alkaline earth metal salts) either before, during or after polycondensation.

This object is accomplished by an aromatic polyamide composition comprising an aromatic polyamide and a disulphimide of the formula:

X-R-SOz-lf-SOg-Rl-Y z in which R and R, which may be the same or different, represent divalent aromatic radicals, X represents hydrogen or a group of the formula SO Z or SO NH Y represents hydrogen, a group of the formula:

/S 0 2NS O z-R X Z n l or a group of the formula:

-/S O r-III-fi O zR-S O2-IIT-S O2R-\X z z I. Z represents an alkali metal'atom or an alkaline earth metal atom linked to a further disulphimide radical of the formula:

and n has a value from 0 to 50,

said disulphimide being present in said composition in such an amount, that said composition contains 50 to 500 m.Equ. of disulphimide groups per kg.

These aromatic polyamides having an aflinity for basic dyes are obtained by incorporating a disulphimide having the general formula:

wherein X, Y, Z, R and R' have the meanings given in claim 1, into an aromatic polyamide material selected from the group consisting of an aromatic polyamide and an aromatic polyamide-forming material, in such a quantity as to provide from 50 to 500 m.Equ. of disulphimide units per kilogram of polyamide composition, said incorporating being effected, before, during or after polycondensation.

In the context of the invention, aromatic polyamides include both fully aromatic and also aromatic heterocyclecontaining polyamides.

More particularly, the disulphimide which can be used in accordance with the invention can also be represented by the general formulae:

In these formulae:

Ar and Ar, which can be the same or different, represent monovalent aromatic radicals which can optionally be substituted by inert groups, for example alkyl radicals or halogen atoms, carboxylic ester or alkoxy groups,

Ar and Ar, which can be the same or difierent, represent divalent aromatic radicals, for example 1,3-phenylene, 1,5-naphthylene, 2,6-naphthylene and the following divalent radicals:

Z represents an alkali metal or alkaline earth metal,

X represents a group of the formula -SO' Z or --SO NH and m represents an integer from 1 to 50.

Production of the disulphimides which can be used in accordance with the invention is known from the literature, and is preferably carried out by condensing aromatic sulphonic acid chlorides with aromatic sulphonamides in an aqueous alkaline medium (Ber., 75, 532 (1942)). They can, however, also be produced by other processes, for example by reacting aromatic sulphonyl thionyl amines with aromatic sulphonic acids (German patent specification No. 1,235,300). In the production of the polymeric disulphimides (formula III), the average molecular weight, or n, can be varied within wide limits. The maximum average molecular weights of the polydisulphimides are obtained when a disulpho chloride and disulphonimide are condensed in a molar ratio of 1:1. This is not absolutely essential, however, because the lower molecular weight products obtained when other molar ratios are used can also be readily employed.

In the context of the present invention, polyamides include fully aromatic or aromatic heterocycle-containing polyamides which can be obtained by interfacial polycondensation, or preferably by condensation in solution, from aromatic or from aromatic heterocycle-containing diamines and dicarboxylic acid dihalides and which are described, for example, in U.S. patent specifications No. 3,094,511 and 3,376,268; in French patent specifications No. 1,199,458 and 1,430,480; in Belgian patent specifications No. 718,033, 718,034 and 742,311; and in German Ofi'enlegungsschrift 1,946,789 and 1,953,358.

The manner or incorporation of the disulphimides is by no means critical and, in the case of condensation in solution, can be carried out at almost any time before, during or, preferably, after condensation. The mono-, dior poly-disulphimides (optionally in the form of their alkali metal or alkaline earth metal salts) can be introduced in the form of solid substances, although they are preferably added in solution in the same polar organic solvent which was used for condensation, in order to guarantee complete admixture. Polyamides produced by interfacial polycondensation are dissolved in a polar organic solvent, preferably N-methyl pyrrolidone or dimethyl acetamide, optionally with the assistance of a solution promoter, for example an alkali metal or alkaline earth metal halide, and the resulting solution is thoroughly mixed before shaping with an alkali metal or alkaline earth metal salt of a mono-, dior poly-disulphimide.

To obtain a high degree of aflinity for dyes, the disulphimide compound has to be incorporated in such a quantity that 1 kg. of polyamide compositions contains from 50 to 500 m.Equ., preferably from 150 to 350 m.Equ., of acid groups.

It is possible in this way to obtain polyamide compositions with a high affinity for basic dyes which can be readily processed into shaped articles such as filaments, fibres and films. These products show extremely favorable mechanical and thermal properties. For example, filaments obtained from these materials show considerably better tensile strength than filaments obtained from copolyamides containing acid groups.

The following examples, in which the relative viscosities quoted were measured on a 0.5% solution of the particular polyamide in N-methyl pyrrolidone at a temperature of 20 C., are to further illustrate the invention without limiting it.

EXAMPLE 1 134 parts by weight of 3-(p-aminophenyl)-7-amino- 2,4-(lH,3H)-quinazolindione were introduced into 707 parts by weight of absolute dimethyl acetamide, followed by the addition, in portions with continuous stirring at 5 to 10 C., of 101.5 parts by weight of isophthalic acid dichloride. The polyamide solution became so highly viscous that altogether another 200 parts by weight of dimethyl acetamide had to be gradually added in order to dilute the solution. To neutralize the hydrochloric acid formed, 58 parts by weight of propylene oxide were stirred in. This was followed by the addition of a solution of 13 parts by weight of bis-(p-tolyl)-disulphimide (M.P. had a viscosity 1;:1535 poises at 20 C. (n, '=1.9), amide.

Filaments were spun from this polyamide solution which had a viscosity 1 :1535 poises at 20 C. (1;, ;=1.9), through a 10-hole spinneret into an aqueous precipitation bath having a temperature of 20 C. The draw-off rate amounted to 10 m./min. After a two-stage stretching operation in boiling water in a ratio 1:15 and then on a heating bow at 230 to 290 C. in a ratio 121.3 to 1.4, filaments with a tensile strength of 4.7 to 5.3 g./dtex. were obtained. They had a breaking elongation of from 5 to 6%.

10 g. batches of fibres of this disulphimide-modified polyamide and the unmodified condensate of 3-(paminophenyl) -7-amino-2,4-( 1H,3H -quinazolindione and isophthalic acid dichloride were dyed with Astrazonrot RL (Colour Index I, p. 162) at 120 C. The dye bath was adjusted to pH 4.5 and left standing for 1.5 hours at 120 C.

In order precisely to determine the greater affinity for dyes, 500 mg. batches of the treated fibres weer dissolved in 25 cc. of dimethyl acetamide and the extinction values were measured in a Photometer (BKF, a product of Messr. Kipp und Zonen) at 475 m in comparison with pure dimethyl acetamide. In the case of the disulphimidemodified polyamide, the extinctions amounted to E=1.0 as against E=0.1 for the unmodified polyamide.

The 3 (p-aminophenyl)-7-amino-2,4-(1H,3H)-quinazolindione (M.P. above 360 C.) used for polycondensation was obtained by the catalytic reduction of the corresponding dinitro compound (M.P. 339 to 341 C.) which 'was in turn obtained by reacting 4-nitroanthranilic acid with p-nitrophenyl isocyanate.

EXAMPLE 2 750 parts by weight of 3-(p-aminophenyl)-7-arnino-2,4- (1H,3H)-quinazolindione were condensed, as in Example 1, with 568 parts by weight of isophthalic acid dichloride in 4260 parts by weight of dimethyl acetamide. The polyamide solution became so highly viscous that another 1800 parts by weight of dimethyl acetamide had to be gradually added. The hydrochloric acid formed during condensation was neutralized by 325 parts by weight of propylene oxide. A solution of 72.8 parts by weight of bis-(p tolyl)-disulphimide in dimethyl acetamide was then stirred Filaments were dry-spun from this polyamide solution which had a viscosity =1620 poise at 20 C. (1;, ;=l.91) through a 72-hole spinneret. The shaft temperature was 215 C. and the draw-off rate was m./ min. Filaments with a strength of 3.6 to 4 g./dtex. at 7 to 8% elongation were obtained.

Comparative dyeing tests were also carried out with these polyamide filaments as described in Example 1. A solution of the filaments, dyed with the same dye as in Example 1, in dimethyl acetamide had an extinction of E=1.75 (as against E=0.1 for a solution of the unmodified polycondensate).

A neutral polyamide solution was prepared as described in Example 1 by condensing 134 parts by Weight of 3-(paminophenyl)-7-amino 2,4 quinazolindione with 101.5 parts by weight of isophthalic acid dichloride in dimethyl acetamide. A solution of 22 parts by weight of dinaphthyl- (1)-disulphimide (M.P. 215 to 218 C.) in dimethyl acetamide was then stirred into this neutral polyamide solution.

Filaments with a tensile strength of 4.0 to 4.5 g./dtex. at 3 to 4% elongation were wet-spun from this polyamide solution (7;:820 poises at 20 C., 1 ;=1.6) as in Example 1.

Comparative dyeing was carried out by the method described in Example 1. A solution of 500 mg. of the fibres dyed with Astrazonrot RL in dimethyl acetamide had an extinction of E=1.25 as against E=0.1 for a solution of the unmodified polyamide.

EXAMPLE 4 solution of 500 mg. of the dyed fibres in 25 ml. of dimethyl acetamide.

EXAMPLE 5 Instead of di-naphthyl-(1)-disulphimide as in Example 3, a solution of 11 parts by weight of a polydisulphimide having the formula:

n is at least 1 and less than 11 in 50 parts by weight of dimethyl acetamide was stirred into a polyamide solution of the same kind. The polydisulphimide (M.P. above 360 C.) was obtained by condensing m-phenylene disulphochloride with m-phenylene disulphonamide in a molar ratio of 6:5 in an alkaline aqueous medium.

Filaments with a strength of 3.9 to 4.4 g./dtex. at 4% elongation were wet-spun from the polyamide solution which had a viscosity of 1150 poises (a =1.88') and a solids content of 18.5%

Comparative dyeing with Astrazonrot RL carried out as in Example 1 produced an extinction of E=0.8 for a solution of 500 mg. of the dyed fibres in 25 ml. of dimethyl acetamide.

SOaNB EXAMPLE 6 If the diamine used in Example 1 is replaced by 179 parts by weight of 2-[3'-(p-aminophenoxy)-phenyl]-3- methyl-6-amino-4(3H)-quinazolone (M.P. 276 to 279 C.) condensed with 101.5 parts by weight of terephthalic acid dichloride, with the procedure otherwise the same, a highly viscous polyamide solution is obtained which was stirred thoroughly into 24.4 parts by weight of di- (p-chlorophenyl)-disulphimide.

Filaments with tensile strengths of from 5.8 to 6.5 g./dtex. for an elongation of 4 to 5% were wet-spun from this polyamide solution (n, =2.35).

Comparative dyeing was also carried out with these polyamide filaments by the method described in Example 1. A solution of 500 mg. of the filaments dyed with Astrazonrot RL in 25 cc. of dimethyl acetamide had an extinction of E=1.75 (as against E=0. 15 for a corresponding solution of the unmodified quinazolone polyamide).

The 2 [3' (p aminophenoxy) phenyl]-3-methyl-6- amino-4(MD-quinazolone (M.P. 276 to 279 C.) used for polycondensation was obtained by reacting S-nitroauthranilic acid and N-methyl-3-(p-nitrophenoxy)-benzimide chloride to form 2-[3'-(p-nitrophenoxy)-pheny1]- 3-methyl-6j-nitro-4(3H)-quinaz0lone (M.P. 248 to 249 C.) which was hydrogenated.

EXAMPLE 7 If the diamine used in Example 1 is replaced by 210 parts by weight of 2 [3'-(p-aminophenoxy)-phenyl]-3- pheny1-7-amino-4(3H)-quinazolone (M.P. 253 to 256 C.) condensed with 101.5 parts by weight of terephthalic acid dichloride, with the procedure otherwise the same, a highly viscous polyamide solution is again obtained into which a solution of 25 parts by weight of 1,5-di-(naphthyl (1) disulphimido)-naphthalene in parts by weight of dimethyl acetamide was stirred.

Filaments with a tensile strength of from 4 to 4.5 g./dtex. were wet-spun from this polyamide solution (Wre1.=

Comparative dyeing was carried out with these polyamide filaments by the method described in Example 1. A solution of 500 mg. of the filaments dyed with Astrazonrot RL in 25 cc. of dimethyl acetamide had an extinction of E=2.05 (as against E=0.15 for a corresponding solution of the unmodified quinazolone polyamide).

The 2-[3' (p-aminophenoxy)-phenyl] 3 phenyl-7- amino-4(3H)-quinazolone (M.P. 253 to 256 C.) was obtained by reacting 4-nitroanthranilic acid and N-phenyl- 3-(p-nitrophenoxy)-benzimide chloride to form 2-[3'- (p-nitrophenoxy) phenyl] 3 phenyl-7-nitro-4(3H)- quinazolone (M.P. 138 to 241 C.) which Was hydrogenated.

EXAMPLE 8 If the diamine used in Example 1 is replaced by 348 parts by weight of a diamine having the formula:

(M.P. 300 to 303 C.) condensed with 101.5 parts by weight of terephthalic acid dichloride, with the procedure otherwise the same, a highly viscous polyamide solution is again obtained into which a solution of 35 parts by weight of 1,5-di-(naphthyl-(1)-disulphimido)-naphthalene in 100 parts by weight of dimethyl acetamide was stirred.

Filaments which, after stretching, had a tensile strength of 3 to 3.5 g./dtex. were wet-spun from this solution.

Comparative dyeing was carried out with these polyamide filaments by the method in Example 1. A solution of 500 mg. of the filaments dyed wit-h Astrazonrot RL in 25 cc. of dimethyl acetamide had an extinction of E=1.65 as against E=0.15 for corresponding solution of the unmodified hydantoin polyamide.

The diamine used for polycondensation (M.P. 300 to 303 C.) was obtained by reacting p-nitrophenyl isocyanate with 1,4-di-(p-cyanoisopropylamino)-phenoxy benzene in a molar ratio of 2:1, followed by ring closure to form the dihydantoin derivative (M.P. 277 to 285 C. which was catalytically reduced.

What we claim is: 1

1. A fibre forming polyamide composition consisting essentially of 1) an aromatic heterocyclic polyamide wherein the heterocyclic ring atoms consist of carbon and nitrogen, and (2) 50-500 milliequivalents per kg. of said composition of a disulphimide selected from the group consisting of bis-(p-tolyl)-disulphimide; dinaphthyl-(1)- disulphimide; 1,3 di(naphthyl-(l)-disulphimido)-benzene; di-(p-chlorophenyl)-disulphimide; 1,5-di(naphthyl- (1)-disulphimido)-naphthalene; and the disulphimide having the formula wherein n is a number which is at least 1 and less than 11.

2. The composition of claim 1 wherein the polyamide is the polymeric reaction product of 3-(p-aminophenyl)- 7-amino-2,4-(lH,3H)-quinazolindione and isophthalic acid dichloride.

3. The composition of claim 1 wherein the disulphimide is bis-(p-tolyD-disulphimide.

4. A filament, fibre or film consisting essentially of the polyamide composition as claimed in claim 1.

5. A fibre consisting essentially of the polyamidc composition as claimed in claim 1.

6. A fibre forming polyamide composition consisting essentially of (a) the polymeric condensation product of 3-(p-aminophenyl) 7 amino 2,4 (1H,3H)- quinazolindione and isophthalic acid dichloride and (b) 50 to 500 milliequivalents per kilogram of said composition of bisp-tolyl) -disulphimide.

7. A fibre forming polyamide composition consisting essentially of (1) an aromatic heterocyclic polyamide wherein the heterocyclic ring atoms consist of carbon and nitrogen, and (2) 50 to 500 milliequivalents per kilogram of said composition of a disulphimide having the formula X-Ar-S o-r r-s 0rAt'--X Z I or 10 x-ru-s Or-liT-S oi-zw-s Or-lTT-S 0r-Ar'-X wherein X is hydrogen or -S0 Z;

Ar, Ar, and Ar" are carbocyclic aromatic radicals;

and Z is hydrogen or alkali metal.

References Cited UNITED STATES PATENTS 2,473,924 6/1948 Walker 260-78 S 3,235,533 2/1966 Brinkman 260-78R 3,661,504 5/1972 Stackman et a1. 260-78S 3,287,324 1l/l966 'Sweeny 260-78 R 3,330,811 7/1967 Craven 260-78 R 3,354,120 11/1967 Bach et a1. 260-78 R 3,467,623 9/1969 Hinderer et al 260-78 R HAROLD D. ANDERSON, Primary Examiner U .8. C1. X.R.

8-178 R; 260-47 CZ, 78 S 

